1. Field of the Invention
The present invention relates to an optical disc player, more particularly to an optical pickup actuator for an optical disc player.
2. Description of the Prior Art
Generally, in various optical disc players such as a mini-disc player, a compact disc player, a laser disc player and a multi-disc player accommodating various discs, an optical pickup device, which is installed directly below an optical recording medium such as an optical disc, performs a track seeking operation moving straight in the radial direction over the disc for seeking a desired track. When the optical pickup device seeks the desired track by the track seeking operation, the optical pickup device performs a track following operation which follows the desired track. In the track following operation, an object lens of the optical pickup device focuses a laser beam on the track which is being followed. When the laser beam is not accurately focused on the track or when a focus of the laser beam is slightly deviated from the track, an optical pickup actuator installed in an optical pickup device performs a focusing operation and a tracking operation. By the focusing and tracking operations of the actuator, the object lens accurately forms a focus of the laser beam on the track while following the track.
U.S. Pat. No. 5,144,607 (granted to Tomoyuki Ishida et al.) discloses a structure of a conventional optical actuator.
FIG. 1 illustrates the conventional optical actuator of an optical pickup device disclosed in the above U.S. patent.
As shown in FIG. 1, the conventional optical pickup actuator includes an object lens bobbin 1 provided with an object lens 2; an object lens supporting member 3 for movably supporting object lens bobbin 1 in focusing and tracking operation directions; focusing coils 6 and tracking coils 7 inserted within object lens bobbin 1; and a magnetic yoke 4 for driving object lens 2 in the focusing and tracking operation directions by forming magnetic flux toward focusing coils 6 and tracking coils 7.
In the above conventional optical pickup actuator, focusing coils 6 and tracking coils 7 are inserted in a coil housing 12 of object lens bobbin 1. Object lens supporting member 3 includes a pair of suspension plates 16; a pair of connecting plates 15 connected to each end of suspension plates 16; and a supporting member 21 inserted between suspension plates 16, thereby forming a rectangular frame.
Further, magnetic yoke 4 includes a bottom plate 220, first and second side plates 221 and 222, a connecting plate 223, and first and second lugs 221a and 222a, thereby forming a rectangular frame.
In the optical pickup actuator having the above structure, since assembled structures have to be provided on both sides of the object lens bobbin, the structure of the optical pickup device becomes complicated, and the overall height and length of the optical pickup actuator are increased.
Further, since the optical pickup actuator includes thin metal plates which are used for increasing the vibration damping efficiency of the suspension plates, its fabrication is difficult and its workability is lowered.
Further, a crosstalk phenomenon is intensified during a signal reproduction since oscillations occur in a focusing direction during a tracking operation as well as in a tracking direction during a focusing operation.